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Workflow Overview

Harnice supports different kinds of products, each of which have basic, distinct properties and store information in their respective ways.

When you "run" Harnice, you're taking the input files of one product, and per a set of rules that you define, output files are generated. This process is called render.

Some products have input and output files that are compatible with each other. Here's the basic workflow.

Workflow overview graph

each gray bar is a render operation on a different product, orange is a user-defined set of render instructions, and blue is a file.

Feature Tree (product as-intended)

Most products have something called a feature tree, which is inspired by 3D cad modeling. It's written directly in Python, and besides from some housekeeping that goes on in the background, is the bulk of what's happening when you render a product.

Inside the feature tree is where you can write your rules on how to build your product. Here's some ideas about how you can express your build intent in logical language:

  • If a harness mates with a device's ethernet socket, specifiy an RJ45 connector on that end of the harness.
  • If a harness contains signals that drive a safety-critical valve, clad that harness with red sleeving.
  • If a system has more than 9 output devices connected to an input device that has 8 inputs, throw an error.
  • If a wire is conducting a thermocouple signal, use special cable and contacts.
  • Specify a label to be applied to a harness whose text is derived from the name of the harness's mating device.
  • If part x is called out as a component of a harness, and part x always requires tool y set to z, add a buildnote with a leader to x that says y-z.

Here's the default feature tree that you get when you try to render a product for the first time. You'd add your logic in here somewhere.

Keep an eye out for how the script references files for the product it's operating on, for other products, and how it generates outputs all in the same stroke as performing the derivation of the part.

Default harness feature tree 
from doctest import run_docstring_examples
import os
from harnice import fileio, state
from harnice.utils import (
    circuit_utils,
    note_utils,
    library_utils,
    feature_tree_utils,
)
from harnice.lists import (
    instances_list, 
    post_harness_instances_list, 
    rev_history, 
    flattened_network, 
    chosen_network,
    available_network
)

{build_macro_block}

# ===========================================================================
#                  HARNESS BUILD RULES
# ===========================================================================
# example: assign a special contact to one specific conductor
instances = fileio.read_tsv("instances list")
circuit_instance = None
connector_at_end_a = None
for instance in instances:
    if instance.get("channel_group") == "channel-MIC2.out1-PREAMP1.in2":
        if instance.get("signal_of_channel_type") == "pos":
            if instance.get("item_type") == "circuit":
                circuit_instance = instance
                connector_at_end_a = instances_list.attribute_of(
                    instance.get("node_at_end_a"), "connector_group"
                )
                new_instance_name = (
                    f"{circuit_instance.get('instance_name')}-special_contact"
                )
                circuit_id = int(circuit_instance.get("circuit_id"))
                instances_list.new_instance(
                    new_instance_name,
                    {
                        "bom_line_number": True,
                        "mpn": "TXPS20",
                        "item_type": "contact",
                        "location_type": "node",
                        "circuit_id": circuit_id,
                        "connector_group": connector_at_end_a,
                    },
                )
                circuit_utils.squeeze_instance_between_ports_in_circuit(
                    new_instance_name, circuit_id, 1
                )

# example: add a backshell
for instance in instances:
    if instance.get("instance_name") in ["X1.B.conn", "PREAMP2.in2.conn"]:
        instances_list.new_instance(
            f"{instance.get('connector_group')}.bs",
            {
                "bom_line_number": True,
                "mpn": "M85049-90_9Z03",
                "item_type": "backshell",
                "parent_instance": instance.get("instance_name"),
                "location_type": "node",
                "connector_group": instance.get("connector_group"),
                "parent_csys_instance_name": (
                    instances_list.instance_in_connector_group_with_item_type(
                        instance.get("connector_group"), "node"
                    )
                ).get("instance_name"),
                "parent_csys_outputcsys_name": "origin",
                "lib_repo": "https://github.com/harnice/harnice",
            },
        )
        instances_list.modify(
            instance.get("instance_name"),
            {
                "parent_csys_instance_name": f"{instance.get('connector_group')}.bs",
                "parent_csys_outputcsys_name": "connector",
            },
        )


# ===========================================================================
#                   IMPORT PARTS FROM LIBRARY FOR GENERAL USE
# ===========================================================================
for instance in fileio.read_tsv("instances list"):
    if instance.get("item_type") in ["connector", "backshell"]:
        if instance.get("instance_name") not in ["X100"]:
            if instance.get("mpn") not in ["TXPA20"]:
                library_utils.pull(instance)

# ===========================================================================
#                  PROCESS HARNESS LAYOUT GRAPH
# ===========================================================================

available_network.validate()

# --- build the chosen network
chosen = chosen_network.build_chosen_network(
    available_path=fileio.path("available network"),
    chosen_segment_ids=["S1", "S2", "S3"],
    chosen_path=fileio.path("chosen network"),
)

# --- modify the chosen network with build rules
# example: rename an auto-generated node to match a connector
for node in chosen.nodes:
    if node.location == (0.0, 0.0, 0.0):
        node.node_id = "X1.connector_node"

# example: add 5% service loop to a segment
for segment in chosen.segments:
    if segment.segment_id == "S2":
        segment.length *= 1.05

# write modifications back to disk
chosen_network.write_chosen_network(chosen, fileio.path("chosen network"))

# --- build the flattened network
flattened_network.build_flattened_network(
    chosen_path=fileio.path("chosen network"),
    flattened_path=fileio.path("flattened network"),
)


# ===========================================================================
#                  ASSING CABLES AND CONDUCTORS
# ===========================================================================

instances = fileio.read_tsv("instances list")
for instance in instances:
    if instance.get("item_type") == "cable":
        for instance2 in instances:
            if instance2.get("parent_instance") == instance.get("instance_name"):
                if instance2.get("item_type") == "conductor":
                    instances_list.modify(
                        instance.get("instance_name"),
                        {
                            "node_at_end_a": instances_list.instance_in_connector_group_with_item_type(
                                instances_list.attribute_of(
                                    instance2.get("node_at_end_a"), "connector_group"
                                ),
                                "node",
                            ).get("instance_name"),
                            "node_at_end_b": instances_list.instance_in_connector_group_with_item_type(
                                instances_list.attribute_of(
                                    instance2.get("node_at_end_b"), "connector_group"
                                ),
                                "node",
                            ).get("instance_name"),
                        },
                    )
                    break

for instance in fileio.read_tsv("instances list"):
    if instance.get("item_type") in ["conductor", "cable"]:
        length = 0
        for instance2 in fileio.read_tsv("instances list"):
            if instance2.get("parent_instance") == instance.get("instance_name"):
                if instance2.get("length", "").strip():
                    if instance.get("item_type") == "conductor":
                        length += float(instance2.get("length").strip())
                    else:
                        length = max(length, float(instance2.get("length").strip()))
        instances_list.modify(instance.get("instance_name"), {"length": length})

# ===========================================================================
#                   ASSIGN BOM LINE NUMBERS
# ===========================================================================
for instance in fileio.read_tsv("instances list"):
    if instance.get("item_type") in ["connector", "cable", "backshell"]:
        instances_list.modify(instance.get("instance_name"), {"bom_line_number": True})
instances_list.assign_bom_line_numbers()

# ===========================================================================
#       ASSIGN PRINT NAMES
# ===========================================================================
for x in range(2):
    for instance in fileio.read_tsv("instances list"):
        if instance.get("item_type") == "connector_cavity":
            instance_name = instance.get("instance_name", "")
            print_name = f"cavity {instance_name.split('.')[-1] if '.' in instance_name else instance_name}"
            instances_list.modify(instance_name, {"print_name": print_name})

        elif instance.get("item_type") in ["conductor", "conductor-segment"]:
            instances_list.modify(
                instance.get("instance_name"),
                {
                    "print_name": f"'{instance.get('cable_identifier')}' of '{instances_list.attribute_of(instance.get('cable_group'), 'print_name')}'"
                },
            )

        elif instance.get("item_type") == "net-channel":
            print_name = f"'{instance.get('this_channel_from_device_channel_id')}' of '{instance.get('this_channel_from_device_refdes')}' to '{instance.get('this_channel_to_device_channel_id')}' of '{instance.get('this_channel_to_device_refdes')}'"
            instances_list.modify(
                instance.get("instance_name"), {"print_name": print_name}
            )

        elif instance.get("item_type") == "net-channel-segment":
            print_name = f"'{instances_list.attribute_of(instance.get('parent_instance'), 'this_channel_from_device_channel_id')}' of '{instances_list.attribute_of(instance.get('parent_instance'), 'this_channel_from_device_refdes')}' to '{instances_list.attribute_of(instance.get('parent_instance'), 'this_channel_to_device_channel_id')}' of '{instances_list.attribute_of(instance.get('parent_instance'), 'this_channel_to_device_refdes')}'"
            instances_list.modify(
                instance.get("instance_name"), {"print_name": print_name}
            )

        elif instance.get("item_type") == "connector":
            print_name = f"{instance.get('connector_group')}"
            instances_list.modify(
                instance.get("instance_name"), {"print_name": print_name}
            )

        elif instance.get("item_type") == "cable-segment":
            print_name = f"{instance.get('cable_group')}"
            instances_list.modify(
                instance.get("instance_name"), {"print_name": print_name}
            )

        elif instance.get("item_type") == "contact":
            print_name = instance.get("mpn")
            instances_list.modify(
                instance.get("instance_name"), {"print_name": print_name}
            )

        else:
            instances_list.modify(
                instance.get("instance_name"),
                {"print_name": instance.get("instance_name")},
            )

# ===========================================================================
#                  ADD BUILD NOTES
# ===========================================================================
for rev_row in fileio.read_tsv("revision history"):
    if rev_row.get("rev") == state.rev:
        note_utils.make_rev_history_notes(rev_row)

for instance in fileio.read_tsv("instances list"):
    for note in note_utils.get_lib_build_notes(instance):
        note_utils.new_note(
            "build_note", note, affectedinstances=[instance.get("instance_name")]
        )

note_utils.assign_buildnote_numbers()

# example: add notes to describe actions
# note_utils.new_note(
#     "build_note",
#     "do this",
#     affectedinstances=["X1.B.conn"]
# )
# note_utils.new_note(
#     "build_note",
#     "do that"
# )

# example: combine buildnotes if their texts are similar
# note_utils.combine_notes("Torque backshell to connector at 40 in-lbs","Torque backshell to connector at about 40 in-lbs")


# ===========================================================================
#                  PUT TOGETHER FORMBOARD SVG INSTANCE CONTENT
# ===========================================================================
instances = fileio.read_tsv("instances list")
note_instances = []
for instance in instances:
    if instance.get("item_type") == "note":
        note_instances.append(note_utils.parse_note_instance(instance))

formboard_overview_instances = []
formboard_detail_instances = []
for instance in instances:
    if instance.get("item_type") not in [
        "connector",
        "backshell",
        "segment",
        "node",
        "origin",
    ]:
        continue

    formboard_overview_instances.append(instance)
    formboard_detail_instances.append(instance)

    detail_flag_note_counter = 1
    overview_flag_note_counter = 1

    if instance.get("item_type") in ["connector", "backshell"]:
        formboard_detail_instances.append(
            note_utils.make_bom_flagnote(
                instance, f"flagnote-{detail_flag_note_counter}"
            )
        )
        detail_flag_note_counter += 1

        formboard_detail_instances.append(
            note_utils.make_part_name_flagnote(
                instance, f"flagnote-{detail_flag_note_counter}"
            )
        )
        detail_flag_note_counter += 1

    if instance.get("item_type") == "connector":
        formboard_overview_instances.append(
            note_utils.make_part_name_flagnote(
                instance, f"flagnote-{overview_flag_note_counter}"
            )
        )
        overview_flag_note_counter += 1

    for note_instance in note_instances:
        if note_instance.get("note_type") == "build_note":
            if instance.get("instance_name") in note_instance.get(
                "note_affected_instances"
            ):
                formboard_detail_instances.append(
                    note_utils.make_buildnote_flagnote(
                        note_instance, instance, f"flagnote-{detail_flag_note_counter}"
                    )
                )
                detail_flag_note_counter += 1

        if note_instance.get("note_type") == "rev_change_callout":
            if instance.get("instance_name") in note_instance.get(
                "note_affected_instances"
            ):
                formboard_detail_instances.append(
                    note_utils.make_rev_change_flagnote(
                        note_instance, instance, f"flagnote-{detail_flag_note_counter}"
                    )
                )
                detail_flag_note_counter += 1

# ===========================================================================
#                  BUILD HARNESS OUTPUTS
# ===========================================================================
instances = fileio.read_tsv("instances list")
scales = {"A": 0.25, "B": 0.3, "C": 1}

feature_tree_utils.run_macro(
    "bom_exporter_bottom_up",
    "harness_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="bom-1",
)
feature_tree_utils.run_macro(
    "tooling_list_exporter",
    "harness_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="tool_list-1",
)
feature_tree_utils.run_macro(
    "standard_harnice_formboard",
    "harness_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="formboard-overview",
    scale=scales.get("A"),
    input_instances=formboard_overview_instances,
)
feature_tree_utils.run_macro(
    "standard_harnice_formboard",
    "harness_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="formboard-detail",
    scale=scales.get("C"),
    input_instances=formboard_detail_instances,
)
feature_tree_utils.run_macro(
    "segment_visualizer",
    "harness_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="cable_layout-1",
    scale=scales.get("A"),
    item_type="cable-segment",
    segment_spacing_inches=0.1,
)
feature_tree_utils.run_macro(
    "segment_visualizer",
    "harness_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="conductor-layout-1",
    scale=scales.get("A"),
    item_type="conductor-segment",
    segment_spacing_inches=0.1,
)
feature_tree_utils.run_macro(
    "segment_visualizer",
    "harness_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="channel-layout-1",
    scale=scales.get("B"),
    item_type="net-channel-segment",
    segment_spacing_inches=0.1,
)
feature_tree_utils.run_macro(
    "circuit_visualizer",
    "harness_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="circuitviz-1",
    input_circuits=instances,
)
feature_tree_utils.run_macro(
    "revision_history_table",
    "harness_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="revhistory-1",
)

build_notes_list_instances = []
for instance in fileio.read_tsv("instances list"):
    if (
        instance.get("item_type") == "note"
        and instance.get("note_type") == "build_note"
    ):
        build_notes_list_instances.append(instance)

feature_tree_utils.run_macro(
    "build_notes_table",
    "harness_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="build_notes_table-1",
    input_instances=build_notes_list_instances,
)
feature_tree_utils.run_macro(
    "pdf_generator",
    "harness_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="pdf_drawing-1",
    scales=scales,
)

{push_block}

# for convenience, move any pdf to the base directory of the harness
feature_tree_utils.copy_pdfs_to_cwd()
Default system feature tree 
from harnice import fileio
from harnice.utils import system_utils, feature_tree_utils
from harnice.lists import instances_list, manifest, channel_map, circuits_list, disconnect_map

#===========================================================================
#                   KICAD PROCESSING
#===========================================================================
feature_tree_utils.run_macro("kicad_pro_to_bom", "system_builder", "https://github.com/harnice/harnice", artifact_id="bom-1")

#===========================================================================
#                   COLLECT AND PULL DEVICES FROM LIBRARY
#===========================================================================
system_utils.make_instances_from_bom()

#===========================================================================
#                   CHANNEL MAPPING
#===========================================================================
feature_tree_utils.run_macro(
    "kicad_pro_to_system_connector_list",
    "system_builder",
    "https://github.com/harnice/harnice",
    artifact_id="system-connector-list-1"
)
manifest.new()
channel_map.new()

#add manual channel map commands here. key=(from_device_refdes, from_device_channel_id)
#channel_map.map(("MIC3", "out1"), ("PREAMP1", "in2"))

#map channels to other compatible channels by sorting alphabetically then mapping compatibles
feature_tree_utils.run_macro(
    "basic_channel_mapper",
    "system_builder",
    "https://github.com/harnice/harnice",
    artifact_id="channel-mapper-1"
)

#if mapped channels must connect via disconnects, add the list of disconnects to the channel map
system_utils.add_chains_to_channel_map()

#map channels that must pass through disconnects to available channels inside disconnects
disconnect_map.new()

#add manual disconnect map commands here
#disconnect_map.already_assigned_disconnects_set_append(('X1', 'ch0'))

#map channels passing through disconnects to available channels inside disconnects
feature_tree_utils.run_macro(
    "disconnect_mapper",
    "system_builder",
    "https://github.com/harnice/harnice",
    artifact_id="disconnect-mapper-1"
)

# ensure channels that are required to be mapped through disconnects are in fact done so
disconnect_map.ensure_requirements_met()

#process channel and disconnect maps to make a list of every circuit in your system
circuits_list.new()

# ===========================================================================
#                   INSTANCES LIST
# ===========================================================================
system_utils.make_instances_for_connectors_cavities_nodes_channels_circuits()

# assign mating connectors
for instance in fileio.read_tsv("instances list"):
    if instance.get("item_type") == "connector":
        if instance.get("this_instance_mating_device_connector_mpn") == "XLR3M":
            instances_list.modify(
                instance.get("instance_name"),
                {
                    "mpn": "D38999_26ZA98PN",
                    "lib_repo": "https://github.com/harnice/harnice",
                },
            )
        elif instance.get("this_instance_mating_device_connector_mpn") == "XLR3F":
            instances_list.modify(
                instance.get("instance_name"),
                {
                    "mpn": "D38999_26ZB98PN",
                    "lib_repo": "https://github.com/harnice/harnice",
                },
            )
        elif instance.get("this_instance_mating_device_connector_mpn") == "DB25M":
            instances_list.modify(
                instance.get("instance_name"),
                {
                    "mpn": "D38999_26ZC35PN",
                    "lib_repo": "https://github.com/harnice/harnice",
                },
            )
        elif instance.get("this_instance_mating_device_connector_mpn") == "DB25F":
            instances_list.modify(
                instance.get("instance_name"),
                {
                    "mpn": "D38999_26ZE6PN",
                    "lib_repo": "https://github.com/harnice/harnice",
                },
            )

# ===========================================================================
#                   ASSIGN CONDUCTORS
# ===========================================================================

# add one conductor per circuit
for instance in fileio.read_tsv("instances list"):
    if instance.get("item_type") == "circuit":
        circuit_id = instance.get("circuit_id")
        conductor_name = f"conductor-{circuit_id}"
        instances_list.new_instance(
            conductor_name,
            {
                "net": instance.get("net"),
                "item_type": "conductor",
                "location_type": "segment",
                "channel_group": instance.get("channel_group"),
                "node_at_end_a": circuit_utils.instance_of_circuit_port_number(
                    circuit_id, 0 # assume the only existing ports at this point are cavities at 0 and 1
                ),
                "node_at_end_b": circuit_utils.instance_of_circuit_port_number(
                    circuit_id, 1
                ),
                "this_channel_from_channel_type": instance.get("this_channel_from_channel_type"),
                "this_channel_to_channel_type": instance.get("this_channel_to_channel_type"),
                "signal_of_channel_type": instance.get("signal_of_channel_type")
            },
        )
        circuit_utils.squeeze_instance_between_ports_in_circuit(
            conductor_name, instance.get("circuit_id"), 1
        )

# define the cable types we want to use here
audio_cable = {
    "lib_repo": "https://github.com/harnice/harnice",
    "mpn": "8762 0602000",
    "lib_subpath": "belden",
}

# assign conductors to cable-id
cable_id_counter = 1
instances = fileio.read_tsv("instances list")
for net in instances_list.list_of_uniques("net"):
    for chgroup in instances_list.list_of_uniques("channel_group"):
        for instance in instances:
            cable_name = f"cable-{cable_id_counter}"

            if instance.get("net") != net:
                continue
            if instance.get("channel_group") != chgroup:
                continue
            if instance.get("item_type") != "conductor":
                continue

            if chtype.parse(instance.get("this_channel_from_channel_type")) in chtype.is_or_is_compatible_with((1, 'https://github.com/harnice/harnice')):
                if instance.get("signal_of_channel_type") in ["pos"]:
                    circuit_utils.assign_cable_conductor(
                        cable_name,
                        ("pair_1", "white"),
                        instance.get("instance_name"),
                        audio_cable,
                        instance.get("net")
                    )
                if instance.get("signal_of_channel_type") in ["neg"]:
                    circuit_utils.assign_cable_conductor(
                        cable_name,
                        ("pair_1", "black"),
                        instance.get("instance_name"),
                        audio_cable,
                        instance.get("net")
                    )
        cable_id_counter += 1 # in this system, each channel gets its own cable.

#===========================================================================
#                   SYSTEM DESIGN CHECKS
#===========================================================================
connector_list = fileio.read_tsv("system connector list")
circuits_list = fileio.read_tsv("circuits list")

#check for circuits with no connectors
system_utils.find_connector_with_no_circuit(connector_list, circuits_list)


# ===========================================================================
#                   ADD STYLING AND PRINT NAMES TO CHANNELS
# ===========================================================================
# assign styling to channels
audio_channel_style = {
    "base_color": "#D59A10",
}
shield_channel_style = {
    "base_color": "#4039A1",
}

for instance in fileio.read_tsv("instances list"):
    if instance.get("item_type") in ["channel", "net-channel"]:
        if instance.get("this_channel_from_channel_type") in ["(1, 'https://github.com/harnice/harnice')", "(2, 'https://github.com/harnice/harnice')"]:
            instances_list.modify(
                instance.get("instance_name"),
                {
                    "appearance": audio_channel_style
                }
            )
        if instance.get("this_channel_from_channel_type") == "(5, 'https://github.com/harnice/harnice')":
            instances_list.modify(
                instance.get("instance_name"),
                {
                    "appearance": shield_channel_style
                }
            )

for instance in fileio.read_tsv("instances list"):
    if instance.get("item_type") == "net-channel":
        instances_list.modify(instance.get("instance_name"), {
            "print_name_at_end_a": instance.get("this_net_from_device_channel_id"),
            "print_name_at_end_b": instance.get("this_net_to_device_channel_id")
        })

# ===========================================================================
#                   SYSTEM ARTIFACT GENERATORS
# ===========================================================================

# map channels passing through disconnects to available channels inside disconnects
# prepare the channel map block diagram overlay
chmap_instances = []
for instance in fileio.read_tsv("instances list"):
    if instance.get("item_type") == "net-channel":
        chmap_instances.append(instance)
feature_tree_utils.run_macro(
    "kicad_sch_net_overlay",
    "system_artifacts",
    "https://github.com/harnice/harnice",
    artifact_id="blockdiagram-chmap-1",
    item_type="net-channel",
    instances=chmap_instances
)

# for convenience, move any pdf to the base directory of the harness
feature_tree_utils.copy_pdfs_to_cwd()

Instances Lists, Signals Lists (product as-designed)

While having a concise set of rules is important to the definition of a product, it is not always sufficient as complete digital representation of the product. There's a difference between "as-intended" (feature tree) vs "as-designed". Harnice produces "as-designed" documentation for products in various formats depending on the product, but the following is a core Harnice design requirement:

There shall always be one single source-of-truth representing the as-designed product, from which all outputs or dependencies are derived.

Here are the "as-designed" filetypes of each designable product:

Product As-designed source of truth
systems, harnesses instances list
device, disconnect signals list

(the other products have more than one but I'm not sure how to defend why that's ok at time of writing)

More information about these:

Instances Lists

Interacting with Instances Lists

An instances list is a list of every physical or notional item, idea, note, part, instruction, circuit, drawing element, thing, concept literally anything that describes how to build that harness or system.

Instances lists are the single comprehensive source of truth for the product you are working on. Other documents like the Feature Tree, etc, build this list, and all output documentation are derived from it.

Columns

Columns are automatically generated when instances_list.new() is called. Additional columns for this kind of list may be added by the user.

Column Description
net the physical harness (represented by a net in Kicad) that this instance is part of
instance_name the unique name of this instance
print_name the non-unique, human-readable name of this instance, used for printing on output documents
bom_line_number if this instance represents a physical procurable good, it gets assigned a line number on a bill of materials
mfg manufacturer of this instance
mpn manufacturer part number
item_type connector, backshell, whatever
parent_instance general purpose reference
location_type each instance is either better represented by one or ther other
segment_group the group of segments that this instance is part of
segment_order the sequential id of this item in its segment group
connector_group a group of co-located parts (connectors, backshells, nodes)
channel_group other instances associated with this one because they are part of the same channel will share this value
circuit_id which signal this component is electrically connected to
circuit_port_number the sequential id of this item in its signal chain
node_at_end_a derived from formboard definition
node_at_end_b derived from formboard definition
print_name_at_end_a human-readable name of this instance if needed, associated with 'node_at_end_a'
print_name_at_end_b human-readable name of this instance if needed, associated with 'node_at_end_b'
parent_csys_instance_name the other instance upon which this instance's location is based
parent_csys_outputcsys_name the specific output coordinate system of the parent that this instance's location is based
translate_x derived from parent_csys and parent_csys_name
translate_y derived from parent_csys and parent_csys_name
rotate_csys derived from parent_csys and parent_csys_name
absolute_rotation manual add, not nominally used unless it's a flagnote, segment, or node
csys_children imported csys children from library attributes file
cable_group other instances associated with this one because they are part of the same cable will share this value
cable_container which cable is this instance physically bundled inside of
cable_identifier cable unique identifier
length derived from formboard definition, the length of a segment
length_tolerance derived from formboard definition, the tolerance on the length of a segment
diameter apparent diameter of a segment <---------- change to print_diameter
appearance see harnice.utils.appearance for details
note_type build_note, rev_note, etc
note_number if there is a counter involved (rev, bom, build_note, etc)
note_parent the instance the note applies to. typically don't use this in the instances list, just note_utils
note_text the content of the note
note_affected_instances list of instances that are affected by the note
lib_repo publically-traceable URL of the library this instance is from
lib_subpath path to the instance within the library (directories between the product type and the part number)
lib_desc description of the instance per the library's revision history
lib_latest_rev the latest revision of the instance that exists in the remote library
lib_rev_used_here the revision of the instance that is currently used in this project
lib_status the status of the instance per the library's revision history
lib_releaseticket documentation needed
lib_datestarted the date this instance was first added to the library
lib_datemodified the date this instance was last modified in the library
lib_datereleased the date this instance was released in the library, if applicable, per the library's revision history
lib_drawnby the name of the person who drew the instance, per the library's revision history
lib_checkedby the name of the person who checked the instance, per the library's revision history
project_editable_lib_modified a flag to indicate if the imported contents do not match the library's version (it's been locally modified)
lib_build_notes recommended build notes that come with the instance from the library
lib_tools recommended tools that come with the instance from the library
attributes_json if an instance is imported with an attributes json attached, it's added here
this_instance_mating_device_refdes if connector, refdes of the device it plugs into
this_instance_mating_device_connector if connector, name of the connector it plugs into
this_instance_mating_device_connector_mpn if connector, mpn of the connector it plugs into
this_net_from_device_refdes if this instance is a channel, circuit, conductor, etc, the refdes of the device it interfaces with, just within this net
this_net_from_device_channel_id if this instance is a channel, circuit, conductor, etc, the channel id in the device it interfaces with, just within this net
this_net_from_device_connector_name if this instance is a channel, circuit, conductor, etc, the name of the connector it interfaces with, just within this net
this_net_to_device_refdes if this instance is a channel, circuit, conductor, etc, the refdes of the device it plugs into just within this net
this_net_to_device_channel_id if this instance is a channel, circuit, conductor, etc, the channel id in the device it plugs into, just within this net
this_net_to_device_connector_name if this instance is a channel, circuit, conductor, etc, the name of the connector it plugs into, just within this net
this_channel_from_device_refdes if this instance is a channel, circuit, conductor, etc, the refdes of the device it interfaces with, at the very end of the channel
this_channel_from_device_channel_id if this instance is a channel, circuit, conductor, etc, the channel id in the device it interfaces with, at the very end of the channel
this_channel_to_device_refdes if this instance is a channel, circuit, conductor, etc, the refdes of the device it plugs into, at the very end of the channel
this_channel_to_device_channel_id if this instance is a channel, circuit, conductor, etc, the channel id in the device it plugs into, at the very end of the channel
this_channel_from_channel_type if this instance is a channel, circuit, conductor, etc, the type of the channel it interfaces with, at the very end of the channel
this_channel_to_channel_type if this instance is a channel, circuit, conductor, etc, the type of the channel it plugs into, at the very end of the channel
signal_of_channel_type if this instance is a channel, circuit, conductor, etc, the signal of the channel it interfaces with, at the very end of the channel
debug the call chain of the function that last modified this instance row
debug_cutoff blank cell to visually cut off the previous column

Commands:

Use the following functions by first importing the module in your script like this: 

from harnice.lists import instances_list
then use as written.

instances_list.new_instance(instance_name, instance_data, ignore_duplicates=False)

Add a new instance to the instances list.

Usage

new_instance(instance_name, instance_data, ignore_duplicates=False)

Args

  • instance_name: String; must be unique within the list.
  • instance_data: Dict of column names to values. May include instance_name; if present it must match the instance_name argument or the code will fail.
  • ignore_duplicates: If True, does nothing when an instance with the same instance_name already exists. If False (default), raises an error on duplicate.

Returns

-1 on success. Raises on invalid input or duplicate (when ignore_duplicates is False).

instances_list.modify(instance_name, instance_data)

Update columns for an existing instance by name.

Args

  • instance_name: The unique name of the instance to modify.
  • instance_data: Dict of column names to new values. Only provided keys are updated; others are unchanged.

Raises

ValueError if no instance with instance_name exists.

instances_list.remove_instance(instance_to_delete)

Remove one instance from the instances list.

Args

  • instance_to_delete: Instance row dict (or any dict) whose instance_name key identifies the instance to remove. Matching is done by instance_name only.
instances_list.new()

Create a new empty instances list file with only the standard header (COLUMNS). Overwrites existing file if present.

instances_list.assign_bom_line_numbers()

Assign sequential BOM line numbers to instances that have bom_line_number set to "True".

Groups by MPN and assigns the same line number to all instances sharing an MPN. Requires every such instance to have a non-empty mpn. Line numbers are assigned in order of first occurrence of each MPN.

Raises

ValueError if any instance marked for BOM has an empty mpn.

instances_list.attribute_of(target_instance, attribute)

Return the value of one column for a single instance.

String values that look like Python literals (list or dict, e.g. starting with `[` or `{`) are parsed with `ast.literal_eval` and the parsed value is returned; otherwise the raw string is returned.

Args

  • target_instance: The instance_name of the instance to look up.
  • attribute: The column name to read (e.g. "mpn", "net").

Returns

The value of that column for the matching instance, or None if not found or attribute missing. List/dict-like strings are returned as list/dict.

instances_list.instance_in_connector_group_with_item_type(connector_group, item_type)

Return the single instance in a connector group with the given item type.

Args

  • connector_group: The connector_group value to match.
  • item_type: The item_type value to match (e.g. connector, backshell).

Returns

The matching instance row dict, or 0 if no match.

Raises

ValueError if connector_group or item_type is blank, or if more than one instance matches.

instances_list.list_of_uniques(attribute)

Return a list of unique non-empty values for one column across all instances.

Args

  • attribute: The column name to collect (e.g. "net", "item_type").

Returns

List of unique values; blanks and None are omitted. Order follows first occurrence in the instances list.

Signals Lists

Interacting with Signals Lists

A Signals List is an exhaustive list of every signal is going into or out of a thing. Signals Lists are the primary way Harnice stores information about devices, and act as the source of truth for devices and disconnects.

Signals List Validation Checks:

(These are automatically validated when you render the device or disconnect that owns the list.)

General Signals List Rules

  • Every signal in the Signals List must be contained by a pre-defined channel type

    Channel Types

    Channel Types

    How are channels mapped?

    How to define a new channel type

    1. In a repository of your choice (or start with harnice_library_public on your own branch), navigate to library_repo/channel_types/channel_types.csv
    2. If you want channel definitions to be private and are therefore working in a private repository, ensure the repo's path is listed in file library_locations.csv (located at root of your harnice source code repo). The first column is the URL or traceable path, and the second column is your local path.
    3. If you find the channel_type you're looking for, temporarily note it as a touple in a notepad somewhere with format (ch_type_id, universal_library_repository).
    4. If you don't find it, make a new one. It's important to try and reduce the number of channel_types in here to reduce complexity, but it's also important that you adhere to strict and true rules about what is allowed to be mapped to what. Modifications and additions to this document should be taken and reviewed very seriously.
    chtype.path(channel_type)

    Resolve the on-disk path to the channel_types.tsv file for a given channel type.

    Args

    • channel_type: Channel type identifier in standard tuple format (channel_type_id, lib_repo) or any string representation that parse can understand (for example "(5, 'https://github.com/harnice/harnice')").

    Returns

    • str: Absolute path to the channel_types/channel_types.tsv file inside the library repository that owns the given channel type.

    Notes

    • This does not filter rows; it only locates the TSV file that defines all channel types for the given lib_repo.
    chtype.parse(val)

    Convert stored string into a tuple (chid:int, lib_repo:str). Handles both single tuples and extracts first tuple from lists.

    chtype.compatibles(channel_type)

    Look up other channel types that are declared as compatible with the given channel type.

    Args

    • channel_type: Channel type identifier in standard tuple format (channel_type_id, lib_repo) or any string representation that parse can understand.

    Returns

    • list[tuple[int, str]]: List of (channel_type_id, lib_repo) tuples taken directly from the compatible_channel_types column of channel_types.tsv. Returns an empty list if no compatibles are defined or if the channel type cannot be found.

    Data format

    • The compatible_channel_types column must be an AST-parseable Python value:
      • Single tuple: (1, "library_repo")
      • List of tuples: [(1, "library_repo"), (2, "library_repo")]
    chtype.attribute(channel_type, attribute)

    Read any additional column from channel_types.tsv for a given channel type.

    Args

    • channel_type: Channel type identifier in standard tuple format (channel_type_id, lib_repo) or any string representation that parse can understand.
    • attribute: Column header name in channel_types.tsv for the value you want to read (for example "description", "notes", "voltage_rating").

    Returns

    • Any: Value stored in the requested attribute column for the matching channel_type_id. Returns an empty list [] if the channel type cannot be found.

    Notes

    • Use this for any per-channel-type metadata you've added as extra columns beyond the core ones like channel_type_id, signals, and compatible_channel_types.
    chtype.signals(channel_type)

    Return the list of signal names associated with a specific channel type.

    Args

    • channel_type: Channel type identifier in standard tuple format (channel_type_id, lib_repo) or any string representation that parse can understand.

    Returns

    • list[str]: List of signal names from the signals column of channel_types.tsv for the matching channel_type_id. If the column is blank or the channel type cannot be found, returns an empty list.

    Data format

    • The signals column is expected to be a comma-separated string, for example: "CAN_H, CAN_L, SHIELD".
    chtype.is_or_is_compatible_with(channel_type)

    Return the given channel type plus all channel types declared as compatible with it.

    Args

    • channel_type: Channel type identifier in standard tuple format (channel_type_id, lib_repo) or any string representation that parse can understand.

    Returns

    • list[tuple[int, str]]: List of (channel_type_id, lib_repo) tuples where the first entry is the parsed channel_type itself and the remaining entries are the compatibles returned by compatibles(channel_type).

    Typical use

    • Use this when validating or mapping channels and you want to treat a channel type as valid if it is either exactly the requested type or explicitly listed as compatible with it.

  • Each signal in the signals list must have every other signal defined by its channel type also present in the list.

    • you can't just define 'positive' if the channel type requires 'positive' and 'negative'

  • Each signal defined in the list is contained by one or more cavities of connectors.

    • you can't "cap off" or not populate one of the signals within a channel because that changes the channel type.

  • Every combination of (channel_id, signal) must be unique within the signals list

    • you can’t have two i.e. “ch1, pos” signals on the same device
    • if you need to break one signal out onto multiple conductors, you'll need to change the channel type to one that defines multiple conductors (i.e. named "ch1, pos-1")

  • You can’t put signals of the same channel on different connectors

    • this is because doing so breaks a lot of internal assumptions Harnice is making while mapping channels.

    • the following two options are recommended work-arounds:

      • Most correct but confusing: Define one channel type per signal, then manually chmap your channels or write a macro for mapping the channels to their respective destinations.

      • Janky but easiest to understand: Define a connector part number that actually represents multiple connectors, while using cavities to reference each connector.

Configurable Device Signals List Rules

It is often useful to be able to change the signals list based on how you're using the device.

  • Each possible configuration of a device must define the same number of conductors throughout the device

    • Changing a configuration must not alter physical build, form, fit, or function, and thus there shall be no conductors that are added or taken away. Maybe some signals are 'unused', but they have to at least be counted for across all configurations.

  • There can be an unlimited number of configuration variables

    • Sometimes just one variable is useful: an SM58 microphone can produce output signals in either balanced vs unbalanced format, depending on how you want to use it.
    • Sometimes there are many variables: suppose you have a mixing console with 32 inputs, and each input can accept either mic or line level inputs depending on the configuration, and each accept either in balanced or unbalanced format signals. Because there's a channel-type defined for each of those options, this would imply 64 configuration variables of the mixing console, each mapping to a unique configuration. This allows the auto channel mapper to find compatibles, and also helps the user track how to set up their device.

Disconnect Signals List Rules

  • “A” and “B” channels of the same disconnect must be compatible with each other

    • this is to ensure when you actually mate the disconnect that the channels inside will be compatible.

Columns

Columns are automatically generated when signals_list.new() is called. Additional columns are not supported and may result in an error when parsing.

Columns of Signals Lists for Devices

Column Description
channel_id Unique identifier for the channel.
signal Name of the electrical function of that signal, as it pertains to its channel type defition. i.e. "positive"
connector_name Unique identifier for the connector that this signal and channel is a part of.
cavity Identifier of the pin, socket, stud, etc, that this signal is internally electrically routed to within its connector.
connector_mpn MPN of the connector in this device (NOT the mating connector).
channel_type The channel type of this signal.
Touple (x, y) where x is the channel id within a library repo and y is the traceable name or url where that channel type library is defined
config_variable Change header or add more headers as needed. Blank: row is true across all values of this field. Otherwise, row is only true when configuration matches the value of this field.

Columns of Signals Lists for Disconnects

Column Description
channel_id Unique identifier for the channel.
signal Name of the electrical function of that signal, as it pertains to its channel type defition. i.e. "positive"
A_cavity Identifier of the pin, socket, stud, etc, that this signal is internally electrically routed to within that side of the connector.
??? question "Why are A and B different here?"
Sometimes it's possible to have connectors that have cavities that may mate electrically, but have different names. For example, suppose two connectors physically mate, but are made by different manufacturers. One manufacturer used lowercase (a, b, c) to reference the cavities but the other used uppercase (A, B, C), or numbers (1, 2, 3), or colors (red, green, blue), etc.
B_cavity Identifier of the pin, socket, stud, etc, that this signal is internally electrically routed to within that side of the connector.
??? question "Why are A and B different here?"
Sometimes it's possible to have connectors that have cavities that may mate electrically, but have different names. For example, suppose two connectors physically mate, but are made by different manufacturers. One manufacturer used lowercase (a, b, c) to reference the cavities but the other used uppercase (A, B, C), or numbers (1, 2, 3), or colors (red, green, blue), etc.
A_connector_mpn MPN of the connector of the harness on this side of the disconnect
A_channel_type The channel type of this side of the discconect.
??? question "Why are A and B different here?"
It's important to keep track of which side has which channel type so that you cannot accidentally flip pins and sockets, for example, by mapping the wrong channel type to the wrong pin gender. Careful validation should be done when mapping channels through disconnects to ensure the disconnects have channels that pass through them in the correct direction.
B_connector_mpn MPN of the connector of the harness on this side of the disconnect
B_channel_type The channel type of this side of the discconect.
??? question "Why are A and B different here?"
It's important to keep track of which side has which channel type so that you cannot accidentally flip pins and sockets, for example, by mapping the wrong channel type to the wrong pin gender. Careful validation should be done when mapping channels through disconnects to ensure the disconnects have channels that pass through them in the correct direction.

Commands:

Use the following functions by first importing the module in your script like this: 

from harnice.lists import signals_list
then use as written.

signals_list.set_list_type(x)

Documentation needed.

signals_list.new()

Creates a new signals TSV file at fileio.path("signals list") with only the header row. Overwrites any existing file.

signals_list.append(**kwargs)

Appends a new row to the signals TSV file. Missing optional fields will be written as empty strings. Raises ValueError if required fields are missing.

Required kwargs: For 'device': channel_id, signal, connector_name, cavity, connector_mpn, channel_type For 'disconnect': A_channel_id, A_signal, A_connector_name, A_cavity, A_connector_mpn, A_channel_type, B_channel_id, B_signal, B_connector_name, B_cavity, B_connector_mpn, B_channel_type

signals_list.cavity_of_signal(channel_id, signal, path_to_signals_list)

Documentation needed.

signals_list.connector_name_of_channel(channel_id, path_to_signals_list)

Documentation needed.

Here's a more detailed diagram of the Harnice workflow including the information covered so far.

Workflow overview graph

Part Numbering

Harnice is designed to work with git: every file format works well with git diff. However, even so, revisions of products are inevitable: if you release a part, start building it, then realize something needs to change, what do you do?

    graph LR
        A[change in design required] --> B{change in form/fit/function?};
        B -->|Yes| C[new revision<br/>ABC-123-rev2];
        B -->|No| D[new part number<br/>ABC-124-rev1];

Change in form, fit and function is a common way for engineers to draw the line between rolling a rev and rolling a part number.

Harnice bakes revisions into part numbers, allowing you to spend your time worrying about engineering, not configuration management.

Before you render a product, the CLI will force you to operate in a “rev folder”. Revision history and statuses of a product is stored in a csv, and Harnice will not render a revision if the "status" column is not blank. That column is where you can record if a revision has been released, superseded, obsoleted, etc.

Mapping Vocabulary

Mapping vocabulary

Vocabulary graphic

Net:

  • Requirement that a harness must exist to connect some connectors together.

Harness:

  • A harness is an assembly of connectors, cables, and other electrical components that connect multiple devices together. It is the physical item that is built and installed in a system.

Channel:

  • A channel is a set of signals that transmit or receive one piece of information, power, etc. They have "channel_types" which define their attributes and compatibility with other channels, and contain a list of required signals (pos, neg)

Signal:

  • A signal is a physical conductive part inside a connector of a device that facilitiates electrical interface with the outside world. A signal must be part of a channel and live inside a connector.

Circuit:

  • A circuit is the requirement that there must exist an electrical path between two signals of connected devices. You can assign conductors or other electrical elements along it. Instances assigned along the circuit have "circuit ids" which represent the order in which the circuit passes through them.

Conductor:

  • A piece of copper, sometimes contained in a cable. Has as many properties, appearances, as you need

Cable:

  • A cable is a COTS or custom physical item, purchased by length, that contains electrical conductors, and are physically installed inside harnesses.

Less important terms

  • Contact:

    • The metal parts of a connector that does the actual mating with the other connector, allows for termination to a wire. Can be pins, sockets, studs, terminals, etc.

  • Cavity:

    • The hole in a connector that physically holds a contact

The Workflow

img_1 img_2 img_3 img_4 img_5 img_6 img_7 img_8 img_9 img_10